05 Camry LE 4 cyl - pinging under light load

[nmikmik]

05 Camry Le 4l - 117k
My wife's car - i noticed slight pinging under light loads 42-43 MPH - 2200 RPM
I know that does not bother her nor it's probably that big of a deal. Just wanted to avoid any damage I can. I do seafoam it at least once a year.
I.e - gas tank 1/2 can can - TB - one 1/2 can. Once ion while I gas her up with premium gas and the ping is gone at that point, but why is it pinging on 87 gas when it's designed to work on it. BTW - i can hear the ping regardless of where she gases up.
Any suggestions?

[somick]

PCV valve?

Vacuum leak?

May be throttle body cleaning.

I would check those items,
Sam

[jdmccright]

I'd pull the plugs to check for deposits...may be getting too hot from encrustation or could be too long. What type of plugs are in there?

A fine water spray into the TB helps clear carbon deposits too.

[nmikmik]

thanks guys!
Did not check the PCV yet, nor for the vacuum leaks
Cleaned the TB about 2 month ago without taking it down though & spark plugs are NGK iridium from what i recall.
I'll try pulling one or two and see if it has any deposits. When I got them replaced about a year ago, the originals where as clean as a whistle.
BTW, i've used a "smoke machine" before to look for the vacuum leaks, what is you way of doing it? Spraying starter fluid all over the engine compartment would not work because I am trying to preserve all those hoses and rubber parts.
Thanks!

[DFBonnett]

Also verify EGR function. A plugged EGR system will cause higher combustion chamber temps resulting in a ping.

[nmikmik]

how do i diagnose plugged up EGR?

[jdmccright]

If there's no CEL (I presume you'd mention it if it was lit), then you'd remove it and look at it. I'd be surprised if it were plugged up on so new a car, but it could be faulty or sticking.

You can use spray carb cleaner or fuel injector cleaner to check for vacuum leaks...better for the rubber and safer than starting fluid. When your'e done, you can choose to spray a coat of silicone spray on the rubber or wipe it down with a rag dampened with it. Go light though since it attracts dust. But in general, underhood rubber components are designed to not need such care. They can resist the heat and fluids found under the hood, but heat is usually the eventual cause of death for most rubber parts, not fluids. Hope this helps!

[nmikmik]

thanks!
I'll try that when she lets me stop it
That's why I am trying to preserve the rubber parts, I live in fairly dry climate and even without much heat (of which here is plenty) it dries out the rubber badly. My Lincoln's air suspention springs were so dry it turned them into mostly rubber dust